8051 micro to TriAC driver

triac driver

Hi to All
can i drive a triac from controller port without a optocoupler and what is the risk of that and please advise me a good interface driver circuit

please help me to understand the sunbber circuit what the function of it

Regards

triac driver circuit

It is not advisable to connect mc directly to mains because any spikes or short circuit may damage whole circuit.

Regards
Nandhu[/quote]

triac driver circuits

You can drive the triac directly from a port of any 8051. The chasis will be live as you'll have to connect the gound of the power supply to the neutral and the phase will be switched by the Triac. Unless the triac develops a "short" for some reason, from the gate to MT1 or MT2, no risks are seen by me in person. Only thing to remember is that the circuit will be live and one should be very cautious handling it. I am using similar circuit to run 6.2 volts 40 nos bulbs on AC220 volts since years. I use 89C52, a ULN2003, a LED, a resistor and then the Triac in sieres.
When you swittch a load through the Triac, a noise will be generated due to the switching and this will be superimposed on the AC lines. The snubber circuit minimises such interference created and keep the ac lines free of noises. But one has to calculate exact values of components to supress the noise and harmonics. Snubber will generally consist of a capacitor and resistor in sieres across the swittching terminals of the triac and again a VDR/ Mov across the same.
Please donot forget the help button. Good luck

triac drive circuit

thanks pranam77 too much ...but can you upload a schematic example and code for this issu to be trully help

thanks again

Regards

interfacing triac with microcontroller

Hai Medtronic
Here is the application schematic what we use, even today without any issues. But about the question of source code, you have to write one or get it written by some one coz i am "zero" in programming. My works are done by my close friend. Sorry for that. Good luck.

microcontroller triac 8051

Opto couplers are used for kind ofprotection but in general cases you can use any kind of current buffer IC or transitor....even a not gate(it acts as buffer for low output current Microcontrollers)....it will keep the microcontroller working

triac driver

I juz wanna start a project of soft starter for 3 phase induction motor. I'm thinking of using 3 triacs as provided by www.fairchildsemi.com/an/AN/AN-3004.pdf or www.nalanda.nitc.ac.in/industry/appnotes/Intersil/an6182.pdf (refer to last few pages - 3 phase control). Which schemetic is better? For the DC logic control of triac driver, can I interface with the 8051. How is it? Can anyone help me? Thanks

triac microcontroller

Hi
Must use optodaic or opto couplers with micro controller pins.
right now i dont have any schematic.
but you may search books on gigapedia.org